Probability, expected frequency and risk

A spinner is spun 180 times and lands on red 45 times. Estimate the probability that it lands on red.

The probability that a light bulb from a factory is faulty is 0.04. Work out the expected number of faulty bulbs in a batch of 650.

A drawing pin is dropped 80 times and lands point up 28 times. Estimate how many times it will land point up in 500 drops.

Four events have probabilities 3/8, 0.4, 35% and 9/20. Which event is most likely?

The probability that a school bus is late on any day is 0.15. How many days out of 40 would you expect the bus to be on time?

A study records how many people caught a cold over one winter. Work out the absolute risk of catching a cold for people who took the supplement.